[georgina_009]

I got d) as an answer. Am i right?

Which of the following sets of substituents are all meta directing in electrophilic aromatic substitution reactions?



  a. -Cl, -NH2, -CH3   
  b. -CH3, -OCH3, -COCH3   
  c. -CH3, -CO2H, -OCH3   
  d. -CN, -NO2, -COCH3   

[D|0XIN]

You may want to try doing a bit more research (ie. as simple as using google and wikipedia) to help find articles that may give you a summary or run-down of this type of question before you have to ask here - you'll get a much quicker response and learn more too!

It took me about 30 seconds to open a new tab in my browser and find the answer. Incase you don't know how, here's something simpler - a one-click answer! =P

http://en.wikipedia.org/wiki/Electrophilic_aromatic_substitution#Meta_directors

Honestly, wikipedia is one of the most useful web resources to find this sort of information besides a good textbook such as "Organic Chemistry" by Clayden et. al.

[Custos]

The whole term "Meta-director" annoys me. There's no such thing as a meta-director. Substituents can deactivate the ortho and para positions leaving the meta position as the preferred site when pushed, but they don't actually activate the meta position.

[RBF]

I don't believe the term 'director' implies either activation or deactivation.  Just that the incoming electrophile will end up in the meta position.  Doesn't really matter that the meta position is 'deactivated least'.  The electrophile is still 'directed' there.

[Custos]

That's true, but it's also linguistic gymnastics. Surely it's more precise to describe substituents as either ortho/para activators or ortho/para deactivators. The use of "meta-director" as a term wrongly leads students to think there are ortho/para activators and meta activators. That is clearly false.